The invention relates to an agrochemical composition. More particularly, this invention relates to a composition which includes both a biologically active ingredient and adjuvants.
In this specification, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not to be taken as an admission that the document, act or item of knowledge or any combination thereof was at the priority date:
(a) part of common general knowledge; or
(b) known to be relevant to an attempt to solve any problem with which this specification is concerned.
Farmers use many agrochemicals to protect or improve their crops. Often, farmers will add adjuvants to a prepared solution containing biologically active ingredients (hereinafter referred to as xe2x80x9cactivesxe2x80x9d) and water to enhance their performance. Sometimes the adjuvants must be added to ensure optimum performance of the actives in a variety of conditions which may otherwise inhibit it, for example, hard water, high temperatures, poor growing conditions.
Whilst the following discussion highlights the invention with relation to herbicides, it is believed that the same principles apply to other actives such as plant hormones, insecticides, crop desiccants or crop defoliants.
Glyphosate is a non-selective herbicide. It is commonly used in domestic, industrial and agricultural situations to control weeds. In the agricultural industry, its use may be limited by the fact that glyphosate will kill most plants including the desired crop depending on the application rate and/or resistance level. Non-selective herbicides can also be used to control weeds in cropping situations where the crop has either been bred or genetically modified to be resistant to the herbicide.
However, when a field is fallow there is no crop for the farmer to be concerned about and glyphosate is often used to prevent weeds from maturing to produce a multitude of seeds which will germinate and cause problems when a crop is later grown on that field.
There is a growing trend to combine herbicides with adjuvants which increase the efficacy of the herbicide. There are two trends in this area. On the one hand, adjuvants are developed as separate compositions which are added to the herbicide at the time of use. On the other hand, formulations have been developed which contain both the herbicide and the adjuvant.
The types of substances which are used as adjuvants include ammonium salts and other plant nutrients, wetting agents, spray drift retardants and lipophilic solvents. Ammonium salts are believed to minimize the deleterious effects of hard water on herbicidal performance and to provide nutrition to the plant which enhances herbicidal performance. Wetting agents improve the leaf coverage of the herbicide. Lipophilic solvents keep the herbicide in liquid form as the herbicide will be ineffective if it dries on the foliage and can also assist the penetration of the herbicide into the plant.
The farmer may combine all these additives with the herbicide when the tank mix is prepared but the farmer may not know whether these components are compatible with each other. Some additives or adjuvants can actually antagonise each other and decrease the activity of the agrochemical. It is also inconvenient since there are several components which must be bought, measured and combined.
Farmers are always looking for more efficacious and convenient ways to enhance the performance of active ingredients. They would also prefer to simply apply a single composition which they know will have optimum performance.
A composition which contains actives when formulated with both plant nutrients and lipophilic solvents may have benefits over other formulations of the same actives or tank mixes of the individual components. However, this has not been possible to evaluate because preparing a homogeneous blend of these components is not easily achieved as they are not readily coupled together.
For example, it is known that formulations of glyphosate and ammonium sulfate can be readily produced because both of these substances are water soluble. However, the polar nature of glyphosate and ammonium sulfate has prevented the formulation of useful compositions which include lipophilic solvents since glyphosate and ammonium sulfate are essentially insoluble in lipophilic solvents.
It has surprisingly been found that a composition which includes one or more oil soluble bases will enable a homogeneous blend to be formed of actives which include organic acids, plant nutrients (e.g. ammonium salts), water and lipophilic solvents.
According to one aspect of the invention, a homogeneous liquid agrochemical composition is provided which comprises:
(a) not in excess of about 25% of one or more organic acids used as an active;
(b) not in excess of about 80% of one or more lipophilic solvents;
(c) not in excess of about 50% of one or more plant nutrients (such as ammonium salts of inorganic anions); and
(d) not in excess of about 50% of one or more oil soluble bases wherein the oil soluble base forms a lipophilic solvent soluble complex with the organic acid;
wherein all proportions are calculated weight/weight on a dry basis based on the total composition.
Preferably, the agrochemical composition comprises:
(a) from 2 to 12% of one or more organic acids used as an active;
(b) from 10 to 50% of one or more lipophilic solvents;
(c) from 2 to 20% of one or more plant nutrients (such as ammonium salts of inorganic anions); and
(d) from 2 to 20% of one or more oil soluble bases.
The organic acids may be selected from the group including glyphosate, gibberellic acid, 2,4-D, dinitrocresol, acifluorfen, benazolin, bilanafos, blasticidin-S, chloramben, chlorflurenol, chlorimuron, chloroacetic acid, chlorthal, clodinafop, cloprop, clopyralid, cloquintocet, cloxyfonac, 4-CPA, flamprop, flamprop-M, fluazifop, fluazifop-P, fluoroglycofen, flupropanate, flurenol, fluroxypyr, fosamine, fosetyl, glufosinate, halosulphuron, haloxyfop, imazapyr, imazaquin, imazethapyr, indol-3-ylacetic acid, 4-indol-3-ylbutyric acid, kasugamycin, quinclorac, quinmerac, quizalofop, quizalofop-P, sulfometuron, 2,3,6-TBA, tecloftalam, thifensulfuron, triclopyr and triflusulfuron. Preferably the organic acid is glyphosate.
The lipophilic solvents may be petroleum fractions, vegetable oils, alkyl esters of fatty acids, fatty alcohols, guerbet alcohols or any combination thereof. The vegetable oils include medium chain triglycerides.
The plant nutrients include ammonium salt of inorganic anions (such as ammonium sulfate and ammonium phosphates) which are known to minimize the deleterious effects of hard water on the performance of actives. Preferably, the ammonium salt is ammonium sulfate. If an anhydrous ammonium salt is used then water may need to be added to the composition. However, if the ammonium salt is already in solution then additional water will probably not be necessary.
The oil soluble bases which may be used include fatty amines, fatty quaternary ammonium hydroxides, fatty betaines and calcium overbasedphenates which will couple with the active acid to form an oil soluble complex. Preferably, N,N-dialkyl fatty amines are used. For example, N,N dimethyllaurylamine or dimethylcocoamine.
According to another preferred embodiment of the invention, the agrochemical composition optionally contains other components to improve the form of the composition. These other components may be added to form a micro-emulsion. Typically, emulsifiers may be used and selected from emulsifiers which may be nonionic, anionic, cationic or amphoteric. Other components which may be added include co-solvents, coupling agents or diluents used to form a micro-emulsion. Preferably, the other components used to form a micro-emulsion with alkyl esters of fatty acids as the lipophilic solvent are a combination of nonionic emulsifiers, cationic emulsifiers and co-solvents. More preferably, with ethyl esters of fatty acids the other components are alkyl polysaccharides, propylene glycol, fatty alkanolamides and cetyl trimethyl anunonium chloride.
Preferably, the nonionic emulsifiers are alkyl polysaccharides, sorbates, polysorbates, alcohol ethoxylates, alkylphenol ethoxylates, glycols or fatty alkanolamides. Alkyl polysaccharides are sometimes called alkyl polyglucosides, alkyl glucosides or alkyl saccharides. An example of a fatty alkanolamide is oleyldiethanolamide. The glycols include propylene glycol, 1,3-butylene glycol, hexylene glycol, and polypropylene glycols.
The cationic emulsifiers are well known to those skilled in the art, and it is recognised there are a multitude of combinations. Preferably, the cationic emulsifiers are quaternary cationic emulsifiers, for example, alkyltrimethylammonium chloride, alkyl dimethylbenzylammonium chloride, alkylpyridium chloride, or alkylimidazolium chloride. More preferably, the cationic emulsifiers are fatty quaternary ammonium chlorides.
According to another preferred embodiment, the agrochemical composition further comprises one or more other available adjuvant components. The adjuvant component may be selected from nonionic emulsifiers, cationic emulsifiers, pH modifiers, spray drift retardants and wetters.
According to a second form of the invention, there is provided a method for enhancing the activity of an organic acid used as an active in an agrochemical composition comprising the step of incorporating the organic acid in a homogeneous liquid agrochemical composition comprising:
(a) not in excess of about 25% of one or more organic acids used as an active;
(b) not in excess of about 80% of one or more lipophilic solvents;
(c) not in excess of about 50% of one or more plant nutrients (such as ammonium salts of inorganic anions); and
(d) not in excess of about 50% of one or more oil soluble bases wherein the oil soluble base forms a lipophilic solvent soluble complex with the organic acid;
wherein all proportions are calculated weight/weight on a dry basis based on the total composition.
According to a third form of the invention, there is provided a method of treating vegetation comprising the step of applying a homogeneous liquid agrochemical composition comprising:
(a) not in excess of about 25% of one or more organic acids used as an active;
(b) not in excess of about 80% of one or more lipophilic solvents;
(c) not in excess of about 50% of one or more plant nutrients (such as ammonium salts of inorganic anions); and
(d) not in excess of about 50% of one or more oil soluble bases wherein the oil soluble base forms a lipophilic solvent soluble complex with the organic acid;
wherein all proportions are calculated weight/weight on a dry basis based on the total composition.